Medical robotic systems such as those used in performing minimally invasive surgical procedures offer many benefits over traditional open surgery techniques, including less pain, shorter hospital stays, quicker return to normal activities, minimal scarring, reduced recovery time, and less injury to tissue. Consequently, demand for minimally invasive surgery using such medical robotic systems is strong and growing.
Examples of medical robotic systems include the daVinci® Surgical System, the daVinci S® Surgical System, and the daVinci® Si HD™ Surgical System from Intuitive Surgical, Inc., of Sunnyvale, Calif. Each of these systems includes a surgeon's workstation, a patient-side cart, a high performance three-dimensional (“3-D”) vision system, and Intuitive Surgical's proprietary EndoWrist® articulating instruments, which are modeled after the human wrist so that when added to the motions of the slave manipulator holding the surgical instrument, they allow at least a full six degrees of freedom of motion, which is comparable to or even greater than the natural motions of open surgery.
The da Vinci® surgeon's workstation has a high-resolution stereoscopic video display. The system offers higher fidelity than polarization, shutter eyeglass, or other 3-D display techniques. Each eye views a separate display that presents the left or right eye perspective through an objective lens and a series of mirrors. The surgeon sits comfortably and looks into this display throughout surgery, making it an ideal place for the surgeon to display and manipulate 3-D intraoperative imagery.
The patient-side cart typically includes three or more slave manipulators for holding and manipulating medical devices such as surgical instruments and image capturing devices for performing and viewing a medical procedure at a surgical site within a patient. To manipulate these medical devices, the surgeon's workstation also includes master control devices which may be selectively associated with the medical devices (and the slave manipulators holding the medical devices) to manipulate them.
In such a medical robotic system, as well as other robotic systems in general, the control of a surgical instrument in response to operator manipulation of a master control device may have a number of definable reference frames and corresponding frame transforms to map points in one frame to corresponding points in another frame. When the position and orientation of one of the frames is unknown, however, precise control of the surgical instrument may be difficult to achieve so that the safety of a patient being treated at the time by the medical robotic system as well as the successful completion of a procedure being performed on the patient may be jeopardized.